Some 3,5-di-t-butylphenyl alkyl ethers wherein the alkyl group contains a carboxyl substituent are known in the art.
Ger. Offen. DE No. 1925423 discloses 5-(3,5-di-butylphenoxy)-2,2-dimethylvaleric acid as being useful for lowering serum glycerides.
G. G. Cross et al., Can. J. Chem., 62(12), 2803-12, describes the nitration of 3,5-di-t-butylphenoxyacetic acid and alpha-(3,5-di-t-butylphenoxy) isobutyric acid to form nitrodienones and nitrodienes.